General Relativity (GR), with or without matter fields, admits a natural extension to a scale invariant theory that requires a dilaton. Here we show that the recently formulated massive GR, minimally coupled to matter, possesses a new global symmetry related to scaling of the reference coordinates with respect to the physical ones. The field enforcing this symmetry, dubbed here quasidilaton, coincides with an ordinary dilaton if only pure gravity is considered, but differs from it when the matter Lagrangian is present. We study (1) theoretical consistency of massive GR with the quasidilaton; (2) consistency with observations for spherically symmetric sources on (nearly) flat backgrounds; (3) cosmological implications of this theory. We find that (I) the theory with the quasidilaton is as consistent as massive GR; (II) the Vainshtein mechanism is generically retained, owing to the fact that in the decoupling limit there is an enhanced symmetry, which turns the quasidilaton into a second Galileon, consistently coupled to a tensor field; (III) unlike in massive GR, there exist flat FRW solutions. In particular, we find self-accelerated solutions and discuss their quadratic perturbations. These solutions are testable by virtue of the different effective Newton’s constants that govern the Hubble expansion and structure growth.

Building on previous work, we explore the parameter space of free functions in nonrelativistic modified gravity theories more widely, showing that in fact the two broad regimes present have similar functional forms between different models. Using different parametrizations, we investigate the effects on scaling tidal stresses as well as attempt to constrain the (hitherto poorly understood) deep modified Newton dynamical (MOND) scaling $C$. We also consider a new intermediate MOND limit in these theories and what it tells us about the transition between these regimes. Finally we suggest a model independent framework, with the aim of constraining the MONDian parameter space using future data, such as the forthcoming LISA Pathfinder mission.

The parameters of the interfering $\psi (3770)$ resonance should be determined from the data on the reactions $e^{+}{e}^{-}\to D\overline{D}$ with the use of the models satisfying the elastic unitarity requirement. The selection of such models can be realized by comparing their predictions with the relevant data on the shape of the $\psi (3770)$ peak in the non-$D\overline{D}$ decay channels. Here, we illustrate this unitarity approach by the example of the most simple variant of the model of the mixed $\psi (3770)$ and $\psi (2S)$ resonances. When new high-statistics data become available, it will be interesting to test this clarity variant.

We study the $W^{+}{W}^{-}\gamma (Z)$ productions at both the CERN Large Hadron Collider (LHC) and the Compact Linear Collider (CLIC) in the framework of the Randall-Sundrum (RS) model. The impacts of the virtual RS Kaluza-Klein (KK) graviton on these processes are studied and compared with the standard model (SM) background. We present the integrated and differential cross sections in both the RS model and the SM. The results show that the relative RS discrepancies at the CLIC differ from those at the LHC, particularly in the transverse momentum and rapidity distributions. We also find that the RS signature performance, as a result of the resonance character of the RS KK-graviton spectrum, is distinctively unlike that in the large extra dimensions model. We conclude that the CLIC, with unprecedented precision and high center-of-mass energy, has a potential advantage over the LHC in exploring the effects of the RS KK graviton on the $W^{+}{W}^{-}\gamma (Z)$ production processes.

By analyzing the external field dependence of correlation functions, the magnetic properties of hadrons can be determined using lattice QCD in magnetic fields. To compute the magnetic moments and polarizabilities of charged hadrons, for example, one requires sufficiently weak magnetic fields. Such field strengths, however, lead to closely spaced Landau levels that are not straightforwardly resolved using standard lattice spectroscopy. Focusing on charged spinless hadrons, we introduce a simple projection technique that can be used to isolate the lowest Landau level. As the technique requires the explicit coordinate-space wave function, we investigate the extent to which the continuum, infinite volume wave function can be employed. We find that, in practice, the effects of discretization can be handled using a perturbative expansion about the continuum. Finite volume corrections are taken into account by using the discrete magnetic translational invariance of the torus. We show that quantized magnetic fields can lead to pernicious volume effects, which depend on the magnetic flux quantum, rather than on the lattice volume.

We compute the full $\mathrm{O}({\alpha }_s)$ supersymmetric QCD corrections for neutralino-stop coannihilation into electroweak gauge and Higgs bosons in the minimal supersymmetric Standard Model. We show that these annihilation channels are phenomenologically relevant within the so-called phenomenological minimal supersymmetric Standard Model, in particular in the light of the observation of a Higgs-like particle with a mass of about 126 GeV at the LHC. We present in detail our calculation, including the renormalization scheme, the infrared treatment, and the kinematical subtleties to be addressed. Numerical results for the coannihilation cross sections and the predicted neutralino relic density are presented. We demonstrate that the impact of including the corrections on the cosmologically preferred region of parameter space is larger than the current experimental uncertainty from WMAP data.

We provide next-to-leading order (NLO) predictions for dark matter (DM) production in association with either a jet or a photon at hadron colliders. In particular we study the production of a pair of fermionic DM particles through a mediator which couples to Standard Model via either a vector, axial-vector, scalar, pseudo-scalar, or gluon-induced coupling. Experimental constraints on the scale of new physics associated with these operators are limited by systematics, highlighting the need for NLO signal modeling. We factorize the NLO QCD and the DM parts of the calculation, allowing the possibility of using the results presented here for a large variety of searches in monojet and monophoton final states. Our results are implemented into the Monte Carlo program MCFM.

We study timelike and spacelike virtual Compton scattering in the generalized Bjorken scaling regime at next-to-leading order in the strong coupling constant, in the medium energy range which will be studied intensely at JLab12 and in the COMPASS-II experiment at CERN. We show that the Born amplitudes get sizeable $O({\alpha }_s)$ corrections and, even at moderate energies, the gluonic contributions are by no means negligible. We stress that the timelike and spacelike cases are complementary and that their difference deserves much special attention.

If the massive neutrinos are the Majorana particles, the unavoidable question of how to pin down the Majorana $CP$-violating phases will eventually become relevant to future neutrino experiments. We argue that a study of neutrino-antineutrino oscillations will greatly help in this regard, although the issue remains purely academic at present. In this work, we first derive the probabilities and $CP$-violating asymmetries of neutrino-antineutrino oscillations in the three-flavor framework, and then illustrate their properties in two special cases: the normal neutrino mass hierarchy with $m_1=0$ and the inverted neutrino mass hierarchy with $m_3=0$. We demonstrate the significant contributions of the Majorana phases to the $CP$-violating asymmetries, even in the absence of the Dirac phase.

The parity and time-reversal invariant effective Lagrangian for a heavy fermion interacting with an Abelian gauge field, i.e., NRQED, is constructed through order $1/M^4$. The implementation of Lorentz invariance in the effective theory becomes nontrivial at this order, and a complete solution for Wilson coefficient constraints is obtained. Matching conditions in the one-fermion sector are presented in terms of form factors and two-photon matrix elements of the nucleon. The extension of NRQED to describe interactions of the heavy fermion with a light fermion is introduced. Sample applications are discussed; these include the computation of nuclear structure effects in atomic bound states, the model-independent analysis of radiative corrections to low-energy lepton-nucleon scattering, and the study of static electromagnetic properties of nucleons.

The phenomenology of the five independent sets of $3\times 3$ quark mass matrices with five texture zeros is carried through in full detail, including predictions for the $CP$-violation asymmetries. Our study is done without any approximation, first analytically and then numerically.

The gluon polarization in the nucleon was measured using open charm production by scattering $160\mathrm{GeV}/c$ polarized muons off longitudinally polarized protons or deuterons. The data were taken by the COMPASS Collaboration between 2002 and 2007. A detailed account is given of the analysis method that includes the application of neural networks. Several decay channels of ${\mathrm{D}}^0$ mesons are investigated. Longitudinal spin asymmetries of the D meson production cross sections are extracted in bins of ${\mathrm{D}}^0$ transverse momentum and energy. At leading order QCD accuracy, the average gluon polarization is determined as $⟨\Delta g/g{⟩}^{\mathrm{LO}}=-0.06\pm 0.21(\mathrm{stat}.)\pm 0.08(\mathrm{syst}.)$ at the scale $⟨{\mu }^2⟩\approx 13(\mathrm{GeV}/c{)}^2$ and an average gluon momentum fraction $⟨x⟩\approx 0.11$. The average gluon polarization is also obtained at next-to-leading order QCD accuracy as $⟨\Delta g/g⟩$ $\mathrm{NLO}=-0.13\pm 0.15(\mathrm{stat}.)\pm 0.15(\mathrm{syst}.)$ at the scale $⟨{\mu }^2⟩\approx 13(\mathrm{GeV}/c{)}^2$ and $⟨x⟩\approx 0.20$.

Correlations of two charged identical kaons (${\mathrm{K}}^{\mathrm{ch}}{\mathrm{K}}^{\mathrm{ch}}$) are measured in $pp$ collisions at $\sqrt{s}=7\mathrm{TeV}$ by the ALICE experiment at the Large Hadron Collider (LHC). One-dimensional ${\mathrm{K}}^{\mathrm{ch}}{\mathrm{K}}^{\mathrm{ch}}$ correlation functions are constructed in three multiplicity and four transverse momentum ranges. The ${\mathrm{K}}^{\mathrm{ch}}{\mathrm{K}}^{\mathrm{ch}}$ femtoscopic source parameters $R$ and $\lambda$ are extracted. The ${\mathrm{K}}^{\mathrm{ch}}{\mathrm{K}}^{\mathrm{ch}}$ correlations show a slight increase of femtoscopic radii with increasing multiplicity and a slight decrease of radii with increasing transverse momentum. These trends are similar to the ones observed for $\pi \pi$ and ${\mathrm{K}}_{\mathrm{s}}^0{\mathrm{K}}_{\mathrm{s}}^0$ correlations in $pp$ and heavy-ion collisions. However at high multiplicities, there is an indication that the one-dimensional correlation radii for charged kaons are larger than those for pions in contrast to what was observed in heavy-ion collisions at the Relativistic Heavy-Ion Collider.

We consider a generalization of an Abelian Chern-Simons-Higgs model by introducing a nonstandard kinetic term. In particular, we show that the Bogomol’nyi equations of the Abelian Higgs theory may be obtained, with their solutions being Nielsen-Olesen vortices with electric charge. In addition, we study the self-duality equations for a generalized nonrelativistic Maxwell-Chern-Simons model.

Local aspects of singular $F$-theory compactifications for supersymmetric grand unified theory model building are fairly well understood in terms of Higgs bundles and their spectral data. Several global issues remain, however, including a description of $G$-fluxes, which are key to constructing chiral matter and stabilizing moduli, and the global realization of $U(1)$ symmetries that can forbid phenomenologically unfavorable couplings. In this paper, we sharpen our earlier proposal for describing $G$-fluxes and $U(1)$s through a distinguished “Tate” divisor. As an application, we give a general discussion of M5-instanton contributions in the presence of $G$-flux and exemplify this in a concrete example, where we comment on the ability of instanton-induced superpotential couplings to stabilize Kähler moduli.

Pulsar timing arrays might detect gravitational waves from massive black hole binaries within this decade. The signal is expected to be an incoherent superposition of several nearly monochromatic waves of different strengths. The brightest sources might be individually resolved, and the overall deconvolved, at least partially, in their individual components. In this paper we extend the maximum-likelihood-based method developed in Babak and Sesana [Phys. Rev. D 85, 044034 (2012)] to search for individual massive black hole binaries in pulsar timing array data. We model the signal as a collection of circular monochromatic binaries, each characterized by three free parameters: two angles defining the sky location and the frequency. We marginalize over all other source parameters, and we apply an efficient multisearch genetic algorithm to maximize the likelihood function and look for sources in synthetic data sets. On data sets characterized by white Gaussian noise plus few injected sources with signal-to-noise ratio in the range 10–60, our search algorithm performs well, recovering all the injections with no false positives. Individual source signal-to-noise ratios are estimated within a few percent of the injected values, sky locations are recovered within a few degrees, and frequencies are determined with sub-Fourier-bin precision.

This paper will deal with an explicit determination of the time evolution of the spin orientation axes and the evolution of the orbital phase in the case of circular orbits under next-to-leading-order spin-orbit interactions. We modify the method of Schneider and Cui proposed [Theoreme über Bewegungsintegrale und ihre Anwendung in Bahntheorien, A Theoretische Geodäsie Vol. 121 (Verlag der Bayerischen Akademie der Wissenschaften, München, Germany, 2005)] to iteratively remove oscillatory terms in the equations of motion for different masses that were not present in the case of equal masses. Our smallness parameter is chosen to be the difference of the symmetric mass ratio to the value $1/4$. Before the first Lie transformation, the set of conserved quantities consists of the total angular momentum $\mathbf{J}$ and the amplitudes of the orbital angular momentum and of the spins, $L$, $S_1$, and $S_2$. In contrast, $S≔|{\mathbf{S}}_1+{\mathbf{S}}_2|$ is not conserved, and we wish to shift its nonconservation to higher orders of the smallness parameter. We perform the iterations explicitly to first order, while performing higher orders would mean no structural difference or harder mathematical difficulties. To apply this method, we develop a canonical system of spin variables reduced by the conservation law of total angular momentum, which is imposed on the phase space as a constraint. The result is an asymptotic series in $ϵ$ that may be truncated appropriately by considering the physical properties of the regarded system.

Short, hard gamma-ray bursts (GRBs) are believed to originate from the coalescence of two neutron stars (NSs) or a NS and a black hole (BH). If this scenario is correct, then short GRBs will be accompanied by the emission of strong gravitational waves (GWs), detectable by GW observatories such as LIGO, Virgo, KAGRA, and LIGO-India. As compared with blind, all-sky, all-time GW searches, externally triggered searches for GW counterparts to short GRBs have the advantages of both significantly reduced detection threshold due to known time and sky location and enhanced GW amplitude because of face-on orientation. Based on the distribution of signal-to-noise ratios in candidate compact binary coalescence events in the most recent joint LIGO-Virgo data, our analytic estimates, and our Monte Carlo simulations, we find an effective sensitive volume for GRB-triggered searches that is $\approx 2\mathrm{times}$ greater than for an all-sky, all-time search. For NS-NS systems, a jet angle ${\theta }_j=20°$, a gamma-ray satellite field of view of 10% of the sky, and priors with generally precessing spin, this doubles the number of NS-NS short-GRB and NS-BH short-GRB associations, to $\sim 3–4\%$ of all detections of NS-NSs and NS-BHs. We also investigate the power of tests for statistical excesses in lists of subthreshold events, and show that these are unlikely to reveal a subthreshold population until finding GW associations to short GRBs is already routine. Finally, we provide useful formulas for calculating the prior distribution of GW amplitudes from a compact binary coalescence, for a given GW detector network and given sky location.

In order to explore some general features of modified theories of gravity which involve higher derivatives and spontaneous Lorentz and/or diffeomorphism symmetry breaking, we study the recently proposed new version of covariant renormalizable gravity (CRG). CRG attains power-counting renormalizability via higher derivatives and introduction of a constrained scalar field and spontaneous symmetry breaking. We obtain an Arnowitt-Deser-Misner representation of the CRG action in four-dimensional spacetime with respect to a foliation of spacetime adapted to the constrained scalar field. The resulting action is analyzed by using Hamiltonian formalism. We discover that CRG contains two extra degrees of freedom. One of them carries negative energy (a ghost) and it will destabilize the theory due to its interactions. This result is in contrast with the original paper [Phys. Lett. B 701, 117 (2011)], where it was concluded that the theory is free of ghosts and renormalizable when we analyze fluctuations on the flat background.